Lorcaserin

What is Lorcaserin?

Lorcaserin is a new treatment for obese patients, which is currently being assessed by the FDA following successful Phase III clinical trials. Lorcaserin has been developed by Arena Pharmaceuticals.

How does Lorcaserin work?

Lorcaserin is the first member of a class of drugs called selective serotonin 2c receptor agonists. Lorcaserin stimulates the serotonin 2c receptor in the brain, including in the hypothalamus - the part of the brain that is associated with mood, appetite and metabolism. The outcome of this action in terms of manifestation is a reduction in appetite.

Is Lorcaserin effective?

Lorcaserin has completed phase III clinic trials and while results have not been as promising as those for other new weight loss drugs currently undergoing scrutiny by the FDA, it does seem to have a good safety profile. Two separate phase III clinic trials (BLOOM and BLOSSOM) evaluated almost 7,200 patients in total over a 2-year period. After 1 year of treatment about two thirds of patients had lost at least 5% of their body weight. The average weight loss was between 17 and 18 pounds and patients saw their blood pressure and heart rate go down.

In the BLOOM trial, 3,182 patients took part, with either a BMI of over 30 or a BMI of between 27 and 30 with another health condition such as Type 2 Diabetes, high blood pressure or high cholesterol. They were given 10mg of Lorcaserin daily over two years. Data showed that after one year:

• 66.4% of patients lost at least 5% of their body weight, compared with 32.1% for those on the placebo
• 36.2% lost at least 10% of their body weight compared with 13.6% for those taking the placebo
• Average weight loss was 17.9 pounds, compared with 7.3 pounds for the placebo group

Is Lorcaserin safe?

Clinical trials are designed not only to determine if a medication works but also to make sure that it is safe for the general public to take.

In trials, Lorcaserin was well tolerated by the patients who took part in the trial and few adverse events were reported when compared with the placebo group. Most side effects were reported in the first year of the two-year trials. Transient headaches were the most common side effects, with 18% of patients experiencing them, compared with 11% in the placebo group. There were also reports of upper respiratory tract infections (14.8% vs. 11.9%.) and nausea (7.5% vs. 5.4%.) These side effects appeared to be the only ones with statistical significance.

No more patients reported feelings of depression, anxiety or suicidal thoughts than in the placebo group (in both groups, reports were infrequent) and the drug has good cardiovascular safety.

Other benefits associated with Lorcaserin

As well has helping people to lose weight, Lorcaserin appears to have other beneficial impacts on health, including:

• Reduction in blood pressure
• Improvement in blood lipids
• Glycaemic indicators
• Markers of cardiovascular risk such as C-reactive protein and Fibrinogen

When will Lorcaserin be Available?

In December 2009 Arena submitted a New Drug Application to the Federal Food and Drug Administration in the US. If Lorcaserin is approved it could be on the market in the US by the end of 2010. We are not yet able to confirm if the company intends to apply for a license in Europe but we consider such a move to be very likely.

Register your interest in Lorcaserin

If you would like to be informed when Lorcaserin is available in the UK under prescription, please complete a weight loss consultation now and you will be added to our database.